The wind tried in vain to whip up leaves that had been tamped and damped by the icy streaks of rain that tore through the sky in brief, flickering bursts. But the leaves lay wetted and dead, slicking the lamplit streets and sidewalks of Chicago, Illinois.

We walked side by side down those streets, past where the streetlamps pause for nature centers and parks, resuming over the concrete river of Lake Shore Drive. We walked under that river, heard the cars screaming overhead, their brakes made shrill by the damp streaking down in bursts and flares.

We walked to the abandoned sanitarium. We walked there to get the bejeez scared out of us.

Each year, the Chicago Park District puts on a massive haunted house at the old sanitarium at Fullerton and the bike path. It opens to the public today, but Wednesday was a free sneak peek night for press, friends of the volunteers and a group from the park district’s special recreation program.

I had swung by the day before, during a bright, sunny bike ride along the lake (the same ride that led to Wednesday’s story about the zoo). I went up to see if I could watch the last-minute prep. I couldn’t, but managed to score the press invite.

The big gates were opened as about a dozen volunteers that I could see painted corpses, hung tattered netting and generally spooked the place up while happy pop music blared in the back.

A day later, those big gates waited for us, made ominous by lighting, crowds and it being a very dark and stormy night.

A group of older ladies — part of a senior fitness group — joked that they could cling to me if it got too scary. I said the same thing back. The crowd sniffed and murmured. Teenagers laughed and shoved. The big gates beckoned. It was our turn. We went in.

Each of the 13 rooms was its own special fright, featuring such chills as undead pirates, psychopaths and evil clowns. As a man with a lifelong phobia of high school theater students (I was attacked as a child by a hard-to-hear staging of “Bye, Bye Birdie”), I was terrified.

Some rooms tried for the ambient creepy (a room I’ll call the Red Room aimed for that). Some tried for stuns and gotchas, the “BOO!” from behind you know is coming but still jump a little when it shows.

One room had a Ringo Starr thing going on. I’m serious.

There will always be things that go bump in the night, from the jolt of a sudden sharp noise from an alley you thought was empty to the spider’s crawl down the neck when you feel you’re being watched but no one’s there. There will always be terrors that make clowns and Ringo seem tame on balance.

But it’s good to know that when a town needs those screams and howls, that spider’s crawl, a legion of volunteers will answer. To make the kids scream and the grown-ups laugh, they’ll become the things that go bump on a dark and stormy night.